Jackfield with split front panel

ABSTRACT

A jackfield with a split front panel so that it can be removed to provide access to jack modules without breaking patch cord interconnections between jacks. Each jack module includes a printed circuit board having a lamp assembly and a tri-jack connected to the front and extending forwardly. The printed circuit boards are hard wired at the back of the jackfield and the printed circuit boards route the circuits to the tri-jack and the lamp assembly. To remove just a tri-jack, it is pulled forwardly after the split front panel is removed. A lateral bracket retains the printed circuit board to prevent it from being pulled forwardly. To remove the entire jack module, the wire wraps are disconnected from the back of the printed circuit board and the retaining bracket is removed. Then, the entire module can be slid forwardly in its guide slot. When a module is inserted, conductor pads on the printed circuit board automatically align and electrically mate with slidably engageable bus terminals to provide -48 volts DC and ground for lighting the lamp.

BACKGROUND OF THE INVENTION

The field of the invention generally relates to electrical jacks, andmore particularly to jackfields which include a plurality of jacks in ajack housing or jack panel.

There is widespread usage of electrical jacks that have switchesactivated by inserting plugs through jack sleeves in the face plate ofeach jack. For example, one type of jack which is commonly referred toas a tri-jack has a vertically elongated face plate with threevertically aligned jack sleeves. Commonly, the top jack sleeve is usedfor monitoring the jack circuit, while the bottom two jack sleeves areused for interconnecting circuits such as between different tri-jacksusing a patch cord with plugs on the ends. The circuits are typicallydigital or voice frequency and are used in such applications as, forexample, telephone central offices, testing and patch panels, computerand data processing equipment, multiplex gear, and commercial andindustrial patching and control applications.

Commonly, a jackfield has input and output circuits connected at theback, and the front is covered by a panel that has apertures throughwhich the individual jack sleeves extend so that patch cord plugs can beinserted. One such jackfield is described in U.S. patent applicationSer. No. 14,909, filed Feb. 13, 1987. It has significant advantage overearlier jackfields because, among other reasons, the tri-jacks haverearwardly extending pins that insert into a connector of a printedcircuit board. Accordingly, the tri-jacks can easily be removed andreplaced without disconnecting and reconnecting hard wiring such as wirewraps. This feature is particularly important because the tri-jacks havea higher failure rate than the other jackfield components due to theirmoving mechanical switches. Accordingly, the tri-jacks have to bereplaced more often. Also, tri-jacks are changed in order to alter thecircuit configuration of the tri-jack. However, one drawback of theabove-described jackfield is that before the tri-jacks can be removed orinserted, the patch cords have to be removed so that the front panel canbe taken off to expose the tri-jacks. This means that any time atri-jack is to be removed or replaced, all of the patch cordinterconnected active circuits must be disrupted.

SUMMARY OF THE INVENTION

It is an object of the invention to provide a jackfield having aplurality of jacks that can easily be removed from the front of thejackfield housing.

It is also an object of the invention to provide a jackfield having aplurality of individual jacks that can be removed from the front withoutdisrupting patched interconnections between other jacks.

It is a further object of the invention to provide a jackfield having afront panel that is split into top and bottom independently removablesections so that the front panel can be removed without firstdisconnecting patch cords interconnecting jacks.

These and other objects are provided by the invention which defines anelectrical jackfield comprising a plurality of electrical jackspositioned side-by-side, each of the jacks having a forward facingvertically elongated face plate having at least one horizontal jacksleeve adapted for receiving the plug of an interconnecting cable, and ahousing for encasing the electrical jacks, the housing comprising firstand second front panels, the first panel covering a top portion of theface plates of the jacks above the jack sleeves and the second frontpanel covering a bottom portion of the face plates of the jacks belowthe jack sleeves, the first and second front panels being independentlyremovable wherein the first and second front panels can be removedwithout first unplugging plugs that are inserted in the jack sleeves. Itis preferable that the jack sleeves have collar portions projectingforwardly from the face plates, and the first panel have a bottom edgewith a plurality of notches for engaging the tops of the collar portionswhile the second panel have a top edge with a plurality of notches forengaging bottoms of the collar portions, the jacks being clamped inhorizontal and vertical alignment by the first and second panels. It isalso preferable that the first panel have an elongated lateral windowand each of the jacks have a corresponding lamp positioned thereabove,each of the lamps having a forwardly projecting neck extending throughthe window of the first panel. As a result, the front panels can beremoved to expose the tri-jacks for removal or insertion withoutdisrupting interconnected circuits between other jacks.

The invention may also be practiced by an electrical jackfieldcomprising a plurality of electrical jacks each having a verticallyelongated face bracket with at least two vertically aligned horizontaljack sleeves for receiving patch cord plugs, the jacks being positionedside-by-side with the face brackets being adjacent to each other, and ahousing for encasing the electrical jacks, the housing comprising a toppanel covering portions of the face brackets above the jack sleeves anda bottom front panel covering portions of the face brackets below thejack sleeves, the top and bottom panels being independently removablewherein the top and bottom front panels can be removed while leavinginterconnecting patch cords inserted into jack sleeves. It is preferablethat the jack sleeves on each of the jacks have collar portionsextending forwardly from the face bracket, the top panel having a bottomedge with a plurality of downwardly facing semicircular notches engagingthe collar portions of the top jack sleeve of each of the jacks and thebottom panel having a top edge with a plurality of upwardly facingsemicircular notches engaging the collar portions of the bottom jacksleeve of each of the jacks wherein the jacks are clamped by the top andbottom panels. Accordingly, the fronts of the jacks are held in securedhorizontal and vertical alignment by the clamping of the top and bottompanels onto the collar portions of the jacks. It is preferable that eachof the jacks have three jack sleeves such as is commonly referred to asa tri-jack. It is also preferable that the face brackets have a built-upshoulder extending between the top jack sleeve and the bottom jacksleeve. Preferably, the shoulder is at the same level as the top andbottom panels thereby giving the appearance of a unitary front panel.Also, it is preferable that the top panel have a horizontally elonggatedwindow and each of the jacks have a corresponding lamp positionedthereabove, each of the lamps having a forwardly projecting neckextending through the window. Also, it is preferable that the necks berectangular and be clamped between adjacent necks and the top and bottomof the window. Further, it is preferable that the top and bottom panelsmate with each other at regions laterally to the sides of the pluralityof jacks, and that the top and bottom edges in these lateral regions bebeveled for mating together.

BRIEF DESCRIPTION OF THE DRAWINGS

The above objects and advantages will be more fully understood byreading the Description of the Preferred Embodiment with reference tothe drawings wherein:

FIG. 1 is a front perspective view of a jackfield;

FIG. 2 is an exploded view of a jack module with associated guideapparatus;

FIG. 3 is a side view of a jack module mounted in the jackfield;

FIG. 4 is an exploded view of the lamp assembly;

FIG. 5 is a front sectioned view of a tri-jack;

FIG. 6 is a side sectioned view of the bus horsing;

FIG. 7 is an exploded view of a bus projection and a portion of a bushousinq slot:

FIG. 8 is a front view of a jackfield; and

FIG. 9 is a view taken along line 9--9 of FIG. 8.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings wherein like characters of reference designatelike parts throughout the various views, FIG. 1 shows a frontperspective view of electrical jackfield assembly 10 which includes anenclosure or housing 12 and a plurality of vertically elongated modules14 that are backwardly extending and mounted side-by-side. Housing 12 isan electromagnetic shielded casing and includes top plate 16, sideplates 18, top and bottom rear plates 20 and 22 (FIG. 3), bottom plate24 (FIG. 3), and top and bottom front plates or panels 26 and 28.Typically, jackfield assembly 10 is mounted in a standard 23-inch rack(not shown) and mounting brackets 30 are provided for this purpose. Topand bottom front panels 26 and 28, which will be described in moredetail later herein, are connected to the front using screws 32 or othersuitable fasteners.

Still referring to FIG. 1, a standard jackfield assembly 10 may consistof 56 side-by-side mounted modules, although other numbers could be usedin various configurations. Each module 14 here has three verticallyaligned plug receiving apertures 34a-c or bores, and thus the modules 14are commonly referred to as tri-jack modules. Although the inventioncould be used to advantage with a variety of different types of modules14, here bore 34a is used to monitor the module 14, bore 34b is used topatch a circuit out of module 14, and bore 34c is used to patch acircuit into module 14. Each plug receiving bore 34a-c is surrounded bya cylindrical jack sleeve 36a-c that has a collar 38. Each module 14 hasa lamp assembly 40 with a lamp 42 that protrudes through an elongatedlateral window 44 in the top front panel 26.

Referring to FIG. 2, an exploded view of a tri-jack module 14 withassociated guide apparatus 46 is shown. Tri-jack module includes printedcircuit board 48, a tri-jack assembly 50, a lamp assembly 40, a bottomguide housing 54 for tri-jack assembly 50, and a right-angle connector56.

Printed circuit board 48 is of conventional construction such as amulti-layer epoxy glass board having a plurality of conductor leads 58which are deposited in a predetermined pattern on both sides of printedcircuit board 48. In FIG. 2, only the conductor leads 58 on one side ofprinted circuit board 48 are shown, and it is well known andconventional to interconnect conductor leads 58 from the opposite sideat terminals such as right-angle connector 56 and at conductive eyelets60. Here, the function of printed circuit board 48 is to interconnectwire wrap lugs or pins 62 and 64 through right-angle connector 56 tocorresponding terminal pins 66 of tri-jack assembly 50. Further, as willbe described in detail later herein, printed circuit board 48interconnects conductor pads 68a-c to corresponding terminals of lampassembly 40 and right-angle connector 56.

Still referring to FIG. 2 and also to FIG. 3 which shows a side sectionview of jackfield assembly 10, printed circuit board 48 has top andbottom forwardly projecting posts or necks 70 and 72, respectively,which define a notch 74 therebetween. Also, printed circuit board 48 hastop and bottom rearward projections 76 and 78, respectively, whichdefine a notch 80 therebetween. As can be seen best in FIG. 2, toprearward projection 76 on which wire wrap lugs 62 are mounted extendsmuch further than bottom rearward projection 78 on which wire wrap lugs64 are mounted. Conductor pads 68a-c are positioned inwardly from notch80.

Still referring to FIG. 2, lamp assembly 40 is connected to topforwardly projecting neck 70 of printed circuit board 48. With furtherreference to FIG. 4, there is shown an exploded perspective view of lampassembly 40 from the opposite side of that shown in FIG. 2. Lampassembly 40 includes lamp housing 82, lamp housing retainer 84,conductor strips 86a and b, and a lamp 42. In fabrication, pins 88 oftwo conductor strips 86a and b are inserted through eyelets (not shown)in neck 70 and soldered in place so that conductor strips 86a and b areparallel and extend horizontally forward. Next, lamp housing retainer 84or center lamp post is inserted between conductor strips 86a and b. Lamphousing retainer 84 is a molded plastic part and has two positioningpins 90 extending laterally from a flat side 92 that seats up againstthe neck 70 of printed circuit board 48. Retainer positioning pins 90insert through small holes 94 in neck 70 thereby accurately locatinglamp housing retainer 84 and preventing it from moving in a longitudinalor vertical direction. 0n the side opposite flat side 92 there are aseries of three ramps 98a, b and c, with ramp 98c defining a retainingboss 99 with a flat top terminating at a back side wall 100. The front102 of lamp housing retainer 84 is pointed, and is contacted on top andbottom by contact terminals 104 of conductor strips 86a and b which arespring tensioned against the top and bottom of retainer front 102.

Lamp housing 82 is a plastic molded part that includes a hollow trunk106, upward and lower legs 108 and 110, and a face portion 112. Upperleg 108 has a downwardly facing guide channel 114 or track and lower leghas a corresponding upwardly facing guide channel 116 or track. Channels114 and 116 face each other and are spaced so as to receive respectiveparallel upper and lower edges 118 and 120 of neck 70. In assembly,edges 118 and 120 are seated in respective guide channels 114 and 116,and then lamp housing 82 is pushed back onto neck 70. There is aninterference fit between the inside wall 122 of hollow trunk 106 andlamp housing retainer 84. The three ramps 98a-c guide inside wall 122away from neck 70 and also prevent lamp housing 82 from engaging orbeing snagged on conductor strips 86a and b. Hollow trunk 106 has asmall aperture 124 which aligns with ramps 98a-c. Lamp housing 82 ispushed onto neck 70 until aperture 124 aligns with retaining boss 99 atwhich point edge 126 at the end of channels 114 and 116 engages ashoulder 128 of neck 70. At this position, retaining boss 99 snaps intoaperture 124 due to the interference fit. The back side wall 100 of lamphousing retainer 84 engages the rear edge of aperture 124 and preventslamp housing 84 from being slid off of neck 70. Thus, lamp housing 82 issecurely attached to neck 70 and disengagement of ramp housing 82 fromneck 70 is prevented. Lamp housing has a front central bore (not shown)through which lamp 42 is inserted. Each lamp has a pair of leads (notshown) which respectively insert on the top and bottom at the front 102of lamp housing retainer 84 and are contacted by respective contactterminals 104 of conductor strips 86a and b. At the bottom of lower leg110 is a downwardly facing guide channel 130 or track which, as will bedescribed later herein, functions to mount tri-jack assembly 50. As willbe described later herein, face portion 112 has a rectangular neck 236which inserts through window 44 with shoulder 238 seating up against theback of top front panel 26.

Bottom guide housing 54 is similar although symmetrically different thanlamp housing 82. Bottom guide housing 54 connects onto bottom forwardprojecting neck 72 in the same manner as lamp housing 82 connects ontoneck 70. More specifically, a lamp housing retainer 84 havingpositioning pins 90 is seated against bottom neck 72 and bottom guidehousing 54 having guide channels similar to guide channels 114 and 116is pushed onto neck 72 and locked in place as shown in FIG. 2. Bottomguide housing 54 has an upward facing guide channel 132 or track whichaligns directly under guide channel 130 of lamp housing 82.

Still referring to FIG. 2, and also to FIG. 5 which shows a frontsectioned view of tri-jack assembly 50 mounted as part of tri-jackmodule 14, tri-jack assembly 50 has an elastic molded housing 134 whichdefines the left side wall 136, the roof 138, the floor 140, and thefront face plate or face bracket 142. The right wall 144 is a metalshield with clips 146 that secure it to plastic molded housing 134. Roof138 has a pair of upwardly projected guide rails 148 or runners, andfloor 140 has a pair of downwardly projected guide rails 150 or runners.Rails 148 and 150 are separated into pairs so as to provide surfaceareas for fastening clips 146. As described in U.S. patent applicationSer. No. 14,909, filed Feb. 13, 1987, which is hereby incorporated byreference, right metal wall 144, in addition to providing a shieldbetween tri-jack assemblies 50, als provides a signal ground for plugs(not shown) that are inserted into plug-receiving apertures 34a-c. Facebracket 142 is a vertical partition that mounts jack sleeves 36a-c forplug-receiving apertures 34a-c. Between the collars 38 of jack sleeves36a and 36c are shoulders 152 which are built up more than the ends 154of face bracket 142.

The function and operation of jacks are well known to those skilled inthe art. Although jacks can have a variety of different internal circuitconnections and can be used for a number of different applications, herejacks, in conjunction with printed circuit board conductor leads 58,provide a straight through circuit between wire wrap lugs 62 and 64 fordigital or voice frequency communication signals when plugs are notinserted into plug-receiving apertures 34a-c . In order to interconnectdifferent modules 14, or patch circuits, or to monitor or test circuits,plugs are inserted into plug-receiving apertures 34a-c. By using cablesconnected to the plugs, a straight through circuit path can beinterrupted, and the circuit re-routed to a different jack module 14.Typically, the top aperture 34a is for monitoring, the middle aperture346 is for OUT signals and the bottom aperture 34c is for IN signals.

In assembling a tri-jack module 14, the guide rails 148 are insertedinto guide channel 130 of lamp housing 82 and guide rails 150 areinserted in guide channel 132 of bottom guide housing 54. Then, thetri-jack assembly 50 is pushed in along respective guide channels 130and 132 until terminal pins 66 engage and make electrical contact withinright-angle connector 56. In order to ensure that tri-jack assembly 50is inserted right-side-up, guide rails 148 and 150 are keyed orpolarized. More specifically, as shown in FIG. 2, the back guide rail150 has a rearward notch 156, and guide channel 132 has an upwardlyextending boss 158. If tri-jack assembly were inserted up-side-down, theback guide rail 148, which does not have a corresponding notch, wouldbump against boss 158 thereby preventing further insertion that couldbend or damage terminal pins 66 by not properly aligning withright-angle connector 56. Referring to FIG. 5, there is shown analternate embodiment for keying or polarizing guide rails 148 and 150.More specifically, guide rails 148 on top are laterally wider than guiderails 150 on the bottom, and guide channels 130 and 132 arecorrespondingly grooved. Accordingly, if attempts were made to inserttri-jack assembly 50 up-side-down, guide rail 148 would not insert intoguide channel 132. Thus, tri-jack assembly 50 cannot be inserted in aninverted orientation.

After each tri-jack module 14 including printed circuit board 48,right-angle connector 56, lamp assembly 40, bottom guide housing 54, andtri-jack assembly 50 are fully assembled, the module 14 is ready forinsertion into housing 12. As shown in FIG. 2, guide apparatus 46includes top wafer guide 160, bottom wafer guide 162, and bus housing164. Also referring to FIG. 3, top and bottom wafer guides 160 and 162are respectively mounted on top and bottom plates 16 and 24, and extendlaterally across jackfield housing 12. Top and bottom wafer guides 160and 162 have a plurality of corresponding channels or grooves 166 whichface each other and are aligned to form guide slots for receiving thetop and bottom edges 168 and 170 of printed circuit board 48. Groovedbus housing 164 also extends laterally and has a plurality of channelsor grooves 172 which align with channels 166. As shown in FIG. 3, thereis a step partition 174 which runs laterally along the back of housing12. Bus housing 164 has a horizontal section 176 which seats on top 178of step partition 174. A suitable fastener 180 connects horizontalsection 176 to step partition 174. The channels 172 of bus housing 164are in horizontal section 176 so they engage the under side edge 182 ofthe rearward projection 76 of printed circuit board 48. In summary, thecombination of channels 166 and 172 define guide slots for holdingmodules 14 in vertical alignment, and also align the respective wirewrap lugs 62 and 64 and conductor pads 68a-c to their proper lateralposition. Wire wrap lugs 62 insert through an array of small openings177 in dielectric insulator terminal block 186 and wire wrap lugs 64insert through an array of small openings 177 in dielectric insulatorterminal block 188. Wires (not shown) are then wire wrapped to theappropriate wire wrap lugs 62 and 64 for routing the proper signals.

Still referring to FIGS. 2 and 3 and also to FIGS. 6 and 7 whichrespectively show side sectioned and rear perspective views of bushousing 164, vertical section 190 of bus housing 164 extends downwardlyparallel to front surface of step partition 174. Vertical section 190 isa dielectric insulator and has columns of three slots 192a-c whichrespectively align with channels 172. Each slot 192 has a step 194,ledges 196 at the sides, and stops 198 at the rear. Busses 200a-c areinserted so that a pair of contact springs 202 protrude forwardly fromeach slot 192. More specifically, each bus 200, of which there is onefor each of three horizontal rows of slots 192, has a plurality ofprojections 204 which insert through slots 192 from the rear. Eachprojection 204 has a horizontal portion 206 that wraps up along thesides 208 and extends forwardly from a front edge 210 of the horizontalportion 206. At the back, the sides have respective ears 212 that extendoutwardly, and a pair of contact springs 202 which slant inwardlythrough a contact region 214 where they bow outwardly. The projection204 is pushed into the slot 192 from the rear until the front edge 210contacts step 194 thereby preventing further movement to the front. Atthis position, ears 212 spring outwardly on both sides above ledges 196and engage stops 198 to prevent motion toward the rear. The contactsprings 202 extend forwardly frcm slots 192. The busses 200a-celectrically interconnect or daisy chain each of the projections 204along one of the respective rows of slots 192. At the end, the top bus200a is connected to -48 volts DC, the middle bus 200b is connected toground, and the bottom bus 200c is used for signal ground. Summarizing,each slot 192 of each column has a pair of contact springs 202 extendingforwardly and the springs 202 are firmly secured so that they cannot bepushed backwardly by printed circuit board 48 or drawn forwardly by theremoval of printed circuit board 48. Also, each of the contact springs202 on the top row 192a provides -48 volts DC, each of the contactsprings 202 in the middle row 192b provides ground, and each of thecontact springs 202 in the bottom row 192c provides signal ground. Asmodule 14 is pushed to its fully inserted position as shown in FIG. 3,respective conductor pads 68a-c insert between respective contactsprings 202 pushing them apart and making tensioned electrical contactbetween busses 200a, b and c, and the respective top, middle and bottomconductor pads 68a-c. Further, it is noted that dielectric insulator 188extends upwardly between vertical section 190 of bus housing 164 andstep partitions 174 to prevent busses 200a-c from contacting steppartition 174.

Referring again to FIG. 3, conductor lead 58a on the facing side ofprinted circuit board 48 electrically interconnects conductor pad 68awith conductor strip 86b of lamp assembly 40. Also, conductor lead 58bon the facing side of printed circuit board 48 electricallyinterconnects conductor pad 68b with terminal 216 of right-angleconnector 56. Further, conductor lead 58c, shown as a dotted linebecause it is routed on the opposite side of printed circuit board 48,electrically interconnects conductor strip 86a with terminal 218 ofright-angle connector 56. Although many other circuit configurationscould be used, conductor pads 68a and 68b are electrically connectedacross conductor strips 86a and 86b of lamp assembly 40 when a plug (notshown) is inserted into the top monitor jack sleeve 36a. Morespecifically, when a plug is inserted into jack sleeve 36a, springcontacts (not shown) internal to tri-jack assembly 50 are urged in thevertical direction thereby electrically interconnecting terminals 216and 218 of rightangle connector 56. In this state, conductor pad 68b iselectrically interconnected with conductor strip 86a. As a result, whena plug is inserted into the monitor jack sleeve 36a, -48 volts DC frombus 200a is connected to one side of lamp 42 via conductor pad 68a andconductor lead 58a, and ground from bus 200b is connected to theopposite side of lamp 42 via conductor pad 68b, conductor lead 58b, aninternal circuit of tri-jack assembly 50, and conductor lead 58c.Accordingly, lamp 42 is lit when a plug is inserted into the monitorjack sleeve 36a.

Referring to FIGS. 8 and 9, front and side views of front plates orpanels 26 and 28 are shown. Bottom front panel 28 extends laterallybelow the bottom of jack sleeves 36c and has a scalloped top edge 220defining a series of semicircular notches 222 into which correspondingcollars 38 of jack sleeves 36c fit. Similarly, top panel 26 extendslaterally above the top jack sleeves 36a and has a scalloped bottom edge224 defining a series of semicircular notches 226 into whichcorresponding collars 38 of jack sleeves 36a fit. Bottom panel 28further has upwardly projecting arms 228 at the sides and preferably atthe middle that extend upwardly and mate with top panel 26. Morespecifically, as shown in FIG. 9, the bottom edge 227a of top panel 26and the top edge 227b of bottom panel 28 at the projecting arms 228 arebeveled so that they interlock thereby eliminating any gap therebetweenthat would visually emphasize the fact that the top panel 26 and bottompanel 28 are two separate parts. Further, the shoulder 152 between jacksleeves 36 a and jack sleeves 36c are built up to the level of top andbottom panels 26 and 28 making the front of housing 12 flat so as toprovide the conventional appearance of having one front panel thatcovers the entire front.

Still referring to FIGS. 8 and 9, the front panel is split into toppanel 26 and bottom panel 28 so that tri-jack assemblies 50 and/ortri-jack modules 14 may be removed or inserted from the front withoutdisrupting service to any other active channels in the jackfield 10.More specifically, the front panel consisting of top panel 26 and bottompanel 28 may be removed without first unplugging plugs (not shown) thathave interconnecting cables between different modules 14. Stateddifferently, even though two modules 14 are interconnected by a patchcable at the front, top and bottom panels 26 and 28 can be independentlyremoved without interrupting the interconnection. Once the top andbottom front panels 26 and 28 are removed, tri-jack assemblies 50 and/ortri-jack modules 14 may be removed and replaced from the front, stillwithout interrupting interconnected jack modules 14, unless, of course,the particular module 14 is between the interconnected modules 14 andthe cable is relatively taut thereacross. Another important feature oftop and bottom panels 26 and 28 is that their respective semicircularnotches 222 and 226 clamp each module 14 from the top and bottom lockingit securely in place. In particular, notches 227 and 226 engage sleeves36a and 36c of each tri-jack assembly 50 preventing it from moving orwobbling which may be especially important if some module slots are notfilled with modules 14. In other words, each module 14 is rigidlyaffixed in vertical and horizontal alignment by the combination ofnotches 222 and 226, and channels 166 and 172.

Referring again to FIG. 3, tri-jack assemblies 50 are removed by pullingthem forwardly such that terminal pins 66 slidably disengage fromright-angle connector 56 and respective guide rails 148 and 150 orrunners slide forwardly within guide channels 130 and 132. Front supportplate 232 extends laterally across the front of jackfield assembly 10and engages respective notches 234 of bottom guide housings 54 therebypreventing the printed circuit board 48 and the rest of the module 14from moving forwardly by the force put on right-angle connector 56 bythe removal of a tri-jack assembly 50.

If, instead of removing just tri-jack assembly 50, the intendedoperation is to remove the entire tri-jack module 14 for service orreconfiguration of electrical jackfield assembly 10, two additionalsteps are required. First, the wire wraps are removed from wire wraplugs 62 and 64. Second, front support or retaining plate 232 is removedby removing screws 233. Then, the module 14 is free to be pulledforwardly and removed from housing 12. Wire wrap lugs 62 and 64 slidethrough their respective openings 177 in top and bottom terminal blocksections 186 and 188, and conductor pads 68a-c slide out of engagementwith the respective contact springs 202. For inserting a module 14 inhousing 12, the process is reversed. Specifically, top and bottom edges168 and 170 of printed circuit board 48 are correspondingly insertedinto channels 166 of top and bottom nylon wafer guides 160 and 162, andthe module 14 is pushed longitudinally towards the rear. The under edge182 of rearward projection 76 of printed circuit board 48 engages acorresponding channel 172 in horizontal section 176 of bus housing 164at a position further to the rear. In the installed position, wire wraplugs or pins 62 insert through openings 177 in the array of top terminalblock section 186 and wire wrap lugs or pins 64 insert through openings177 in the array of bottom terminal block section 188. Also, conductorpads 68a-c automatically align with and engage corresponding contactsprings 202 of respective busses 200a-c. Accordingly, -48 volts DC,ground, and signal ground are disengageably provided to the rear ofmodule 14 such that module 14 can be longitudinally inserted and removedfrom the front of housing 12. Wire wrap lugs 62 and 64 are wire wrappedas described earlier herein. Next, after all of the desired modules 14are inserted, front support plate 232 is affixed in place using screws233. Then, the bottom and top front plates 28 and 26 are positioned inplace and screws 32 are used to secure them. The neck 236 of the faceportion 112 of each lamp housing 82 protrudes through window 44 and theback of top front plate 26 seats against shoulder 238 of the faceportion 112 (FIG. 4).

Referring again to FIG. 2, metal plate shields 240 are slidlongitudinally in from the front between the slots for modules 14 duringinitial assembly. Shields 240 function to suppress crosstalk betweenadjacent modules 14. Thin shield slots 242 are cut in between andparallel to channels 166 in guide wafers 160 and 162. Top and bottomedges 244 and 246 of shields 240 slidably engage shield slots 242.Further, shields 240 each have an upper rear projection 248 wit an underedge 250 that slidably engages a guide slot 252 positioned parallel andin between channels 172 of bus housing 164. The under edge 250 of eachshield 240 has a notch 254 which engages a flexible hook 256 extendingfrom the rear of bus housing 164. More specifically, with reference toFIG. 6, the bottom edge 250 of shield 240 rides along ramp 258 duringinitial assembly thereby depressing hook 256. When notch 254 arrives athook 256, hook 256 springs upward into notch 254 and thereby preventsremoval of shield 240 to the front. Accordingly, shields 240 stay inplace in housing 12 even though modules 14 may be removed for repair orreplacement with other types of modules. If shields 240 could be pulledforwardly, a module 14 could be replaced and the shield 240inadvertently left out.

This concludes the description of the preferred embodiment. A reading ofit by those skilled in the art will bring to mind many modifications andalterations without departing from the spirit and scope of theinvention. Accordingly, it is intended that the invention be limitedonly by the appended claims.

What is claimed is:
 1. An electrical jackfield comprising:a plurality ofelectrical jacks positioned side-by-side, each of said jacks having aforward facing vertically elongated face plate having at least onehorizontal jack sleeve adapted for receiving the plug of aninterconnecting cable; an enclosure for receiving said jacks through anopening at one side thereof; and first and second front panels coveringportions of said opening respectively above and below said jack sleeves,said first front panel extending from the tops of said jack sleeves tothe top of said opening and said second front panel extending from thebottoms of said jack sleeves to the bottom of said opening, said firstand second front panels being independently removable wherein said firstand second front panels can be removed without first unplugging those ofsaid plugs that are inserted in said jack sleeves.
 2. An electricaljackfield assembly comprising:a plurality of electrical jacks positionsside-by-side, each of said jacks having a forward facing verticallyelongated face bracket having at least one horizontal jack sleeveadapted for receiving the plug of an interconnecting cable; a housingcomprising an enclosure for receiving said jacks through an opening atone side thereof, said housing further comprising first and second frontpanels covering portions of said opening, said first front panelcovering a top portion of said face brackets of said jacks above saidjack sleeves and the second front panel covering a bottom portion of theface brackets of said jacks below said jack sleeves, said first andsecond front panels being independently removable wherein said first andsecond front panels can be removed without first unplugging those ofsaid plugs that are inserted in said jack sleeves; and said jack sleeveshaving collar portions projecting forwardly from said face brackets,said first panel having a bottom edge with a plurality of semicircularnotches for engaging tops of said collar portions of respective ones ofsaid collars, said second panel having a top edge with a plurality ofsemicircular notches for engaging bottom portions of respective ones ofsaid collars wherein said jacks are clamped in position by said firstand second panels.
 3. An electrical jackfield comprising:a plurality ofelectrical jacks positioned side-by-side, each of said jacks having aforward facing vertically elongated face bracket having at least onehorizontal jack sleeve adapted for receiving the plug of aninterconnecting cable; a housing comprising an enclosure for receivingsaid jacks through an opening at one side thereof, said housing furthercomprising first and second front panels covering portions of saidopening, said first front panel covering a top portion of said facebrackets of said jacks above said jack sleeves and the second frontpanel covering a bottom portion of the face brackets of said jacks belowsaid jack sleeves, said first and second front panels beingindependently removable wherein said first and second front panels canbe removed without first unplugging those of said plugs that areinserted in said jack sleeves; and each of said jacks having acorresponding lamp positioned thereabove, each of said lamps having aforwardly projecting neck, said first panel having an elongated windowsurrounding said necks of said lamps.
 4. An electrical jackfieldcomprising:a plurality of electrical jacks each having a verticallyelongated face bracket with at least two centrally located horizontaljack sleeves for receiving patch cord plugs, said jacks being positionedside-by-side with said face brackets being adjacent to each other; anenclosure for receiving said jacks through an opening at one sidethereof; and top and bottom front panels covering portions of saidopening respectively above and below said jack sleeves of said jacks,said top front panel extending from the top of said opening to adjacentthe top ones of said jack sleeves, said bottom front panel extendingfrom the bottom of said opening to adjacent the bottom ones of said jacksleeves, said top and bottom front panels being independently removablewherein said top and bottom front panels can be removed while leavinginterconnecting patch cord plugs inserted into jack sleeves.
 5. Anelectrical jackfield comprising:a plurality of electrical jacks eachhaving a vertically elongated face bracket with at least two centrallylocated horizontal jack sleeves for receiving patch cord plugs, saidjacks being positioned side-by-side with said face brackets beingadjacent to each other; a housing comprising an enclosure for receivingsaid jacks through an opening at one side thereof, said housing furthercomprising a top front panel covering a portion of said opening abovesaid jack sleeves and a bottom front panel covering a portion of saidopening below said jack sleeves, said top and bottom front panels beingindependently removable wherein said top and bottom front panels can beremoved while leaving interconnecting patch cord plugs inserted intojack sleeves; and said jack sleeves on each of said jacks beingvertically aligned and having collar portions extending forwardly, saidtop panel having a bottom edge with a plurality of downwardly facingsemicircular notches engaging said collar portions of the top jacksleeves of each of said jacks and said bottom panel having a top edgewith a plurality of upwardly facing semicircular notches engaging saidcollar portions of the bottom jack sleeve of each of said jacks.
 6. Theelectrical jackfield recited in claim 5 wherein each of said jacks hasthree jack sleeves.
 7. The electrical jackfield recited in claim 5wherein each of said face brackets has a built-up shoulder extendingfrom the top jack sleeve collar portions to the bottom jack sleevecollar portions.
 8. The electrical jackfield recited in claim 5 whereineach jack has a corresponding lamp positioned thereabove, each of saidlamps having a forwardly projecting neck, said top panel having ahorizontally elongated window surrounding said necks of said lamps. 9.The electrical jackfield recited in claim 5 wherein said top and bottompanels mate with each other at regions laterally to the side of saidplurality of jacks.
 10. The electrical jackfield recited in claim 9wherein the top and bottom edges of said bottom and top panels in saidlateral regions are beveled for mating together.